Friends and family watching as the Paterson Music Project performed during the ceremony Saturday at the Ellison Street facility.

The preschool and elementary school buildings are on Spruce Street; the total enrollment this year will top 800, and there is a waiting list that is particularly long in the lower grades, school officials said.

In many cities, including Newark, charter and traditional schools coexist uneasily, with critics complaining that charter schools siphon resources from the school district. But in Paterson on Saturday, the city’s school board president and mayor came out to celebrate the opening.

“It’s not us versus them,” said Keisha Smith, a school board employee whose daughter attends the charter school. “There are a lot of detractors of charter schools but what people have to understand is that we all have to be proponents of educations.”

At their best, charter schools are supposed to be incubators for innovations that can be adopted by the traditional public schools. There are about 90 charter schools statewide, mostly in poor neighborhoods; the schools’ track records, as measured by improved test scores, have been mixed.

Paterson Mayor Joey Torres said school choice is key in improving Paterson’s struggling schools. He noted that the traditional high schools have been broken up into smaller academies that focus on specific interests, like public safety or the arts.

“This is all about school choice. I embrace the Community Charter School and I embrace the academy model in district schools,” Torres told the crowd gathered across the street from the back of City Hall. “Parents and students need to put themselves in an environment where they succeed.”

There are now four charter schools in Paterson and they educate just under 3,000 students as compared to the 29,000 students enrolled in the city’s traditional public schools.

Charters are public schools — they are funded through taxes — but they operate independent of the local school board and, most often, teachers unions.

The four-story beaux-arts building that houses the middle school is nearly 100 years old and has been a bank, a gym, the annex, and, most recently, a public school. It was derelict when the charter school began renovations, which totaled $850,000, said the school’s founder, Bob Guarasci. He said the funds came from surplus in the school’s operating budget.

“We brought it back to life,” said Guarasci, who is CEO of the New Jersey Community Development Corp. “Schools themselves can be economic engines.”

Mark Valli, CEO of the school, said charters can often be more agile than the bureaucracy of a traditional public school. He noted, for instance, that the school’s music program was funded through a grant.

Valli said the school’s socio-economic makeup of the student body mirrors that of the larger district, as more than 90 percent of students are eligible for free or reduced price lunches because of poverty.

The Community Charter School features an extended school day until 4 p.m., before and after school, summer and weekend programming.

“The entire family is involved in the school,” said Paula Alford, whose 8-year-old son, Dante Johnson, plays cello with the school’s music program. “He feels like this is his second family.”

Talitha Sample, a rising sixth-grader, said she appreciated that the school demanded excellence of her. “When I graduate from high school I want to attend Princeton University and study either medicine or education.”